scholarly journals Potential of ozonation for the degradation of antibiotics in wastewater

2007 ◽  
Vol 55 (12) ◽  
pp. 321-326 ◽  
Author(s):  
V. Yargeau ◽  
C. Leclair
Keyword(s):  
Bacterial Infections ◽  
Reaction Order ◽  
Degradation Products ◽  
Order Reaction ◽  
Published Data ◽  
Second Order Reaction ◽  
Promising Technique ◽  
First Order ◽  
Treatment Conditions ◽  
Ft Ir

Increasing concern in recent years over the occurrence and fate of low-level concentrations of pharmaceuticals in the aquatic environment stimulates research on alternative treatment methods. This paper presents a study of the degradation of sulphamethoxazole, an antibiotic used on humans and animals in order to treat various bacterial infections, by ozonation. After 4.5 min of treatment, the concentration of sulphamethoxazole was below the HPLC detection limit of 0.6 mgL−1, indicating degradation efficiency higher than 99.24%. This value is comparable and in some cases higher than published data on the degradation in drinking water. Kinetic analysis of the data indicated an overall first-order reaction with a rate constant of 1.0594 min−1 at 20 °C. The reaction order differs with the second-order reaction observed by other researchers. This change of reaction order could be explained by the different treatment conditions used. Preliminary analysis using the FT-IR technique was also performed in order to obtain information on the structure of the degradation products. Further analysis using a GC-MS is needed in order to elucidate the structure of the degradation products. Finally, based on the experiments performed, ozonation seems to be a promising technique for the degradation of antibiotics, even in wastewater.

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

Microbial degradation of estrogens using activated sludge and night soil-composting microorganisms

2004 ◽  
Vol 50 (8) ◽  
pp. 153-159 ◽  
Author(s):  
J.H. Shi ◽  
Y. Suzuki ◽  
S. Nakai ◽  
M. Hosomi
Keyword(s):  
Activated Sludge ◽  
Microbial Degradation ◽  
Estrogenic Activity ◽  
Degradation Products ◽  
Order Reaction ◽  
Yeast Two Hybrid ◽  
First Order ◽  
Natural Estrogens ◽  
17Β Estradiol ◽  
Two Hybrid

In order to investigate the potential for microbial degradation of estrogens, and the products formed, activated sludge collected from Korea (ASK) and night soil-composting microorganisms (NSCM) were used to degrade estrogens. Results showed that both ASK and NSCM degraded almost 100% of the natural estrogens estrone (E1), 17β-estradiol (E2), and estriol (E3) from initial concentrations of 20-25 mg/L, while synthetic estrogen, ethynylestradiol (EE2), was not degraded. Analysis of degradation products of E2 by using HPLC-ECD and a consecutive first-order reaction calculation confirmed that E2 was sequentially degraded to E1, which was further degraded to other unknown compounds by ASK and NSCM. We then used the yeast two-hybrid assay to show that the unknown degradation products did not appear to possess estrogenic activity when E1, E2 or E3 were degraded to below the detection limit after 14 days of incubation, indicating that ASK and NSCM not only degrade natural estrogens, but also remove their estrogenic activities.

Thermogravimetric analyses (TGA) of lignins isolated from the residue of corn stover bioethanol (CSB) production

Holzforschung ◽  
2016 ◽  
Vol 70 (12) ◽  
pp. 1175-1182 ◽  
Author(s):  
Yubo Tao ◽  
Shujun Li ◽  
Peng Li ◽  
Qinglin Wu
Keyword(s):  
Benzyl Alcohol ◽  
Corn Stover ◽  
Organic Solvents ◽  
Reaction Order ◽  
Order Reaction ◽  
Regular Form ◽  
Thermogravimetric Analyses ◽  
First Order ◽  
Left Behind ◽  
Kissinger’S Method

Abstract In the course of corn stover bioethanol (CSB) production, a lignin-rich residue is left behind, which is a potential feedstock for biofuel and other high-value products. In the present paper, this residual lignin was separated by precipitation from the alkali-solution and by extraction with organic solvents (benzyl alcohol, dioxane, and ethanol), respectively. Thermogravimetric analyses (TGA) at a heating rate of 30 K min-1 showed that the degradation of all lignins took place in a temperature range between 400 K and 1073 K, with maxima at around 600 K. The char yield of alkali-lignin is higher than that of the CSB residue and the lignins isolated by organic solvents. Derivative TG (DTG) curves reflect well the comprehensive thermal degradation processes. The kinetic parameters according to the Kissinger’s method indicate that the CSB residue and all lignins follow approx. the first-order reaction law, except for benzyl alcohol lignin with n=1.4. As for the effects of separation methods, the DTG curves of benzyl alcohol lignin exhibited a less regular form and its wide temperature profile may have contributed to its apparently higher reaction order.

Studies in the Vulcanization of Rubber. III—Kinetics of Vulcanization of Rubber with Sulfur and Selenium

1930 ◽  
Vol 3 (4) ◽  
pp. 650-659
Author(s):  
John T. Blake
Keyword(s):  
Molecular Weight ◽  
Order Reaction ◽  
Order Equation ◽  
Second Order Reaction ◽  
Experimental Conditions ◽  
Mathematical Basis ◽  
First Order ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization

Abstract A procedure for the determination of combined selenium in rubber has been evolved. The rate of combination of selenium and rubber has been ascertained under certain conditions and shown to follow a first-order equation. A minimum value for the molecular weight of rubber has been estimated. The formation of hard rubber under chosen experimental conditions has been put on a mathematical basis and has been shown to follow a second-order reaction. The soft- and hard-rubber reactions have been shown qualitatively to be successive reactions and the function of accelerators has been discussed. The theory explains the anomalous results obtained by previous investigators.

scholarly journals Partial acidulation of phosphate rock for enhanced phosphorus availability in alluvial soils of Bihar, India

2016 ◽  
Vol 8 (3) ◽  
pp. 1393-1397 ◽  
Author(s):  
Kasturikasen Beura ◽  
Rajeev Padbhushan ◽  
Amit Kumar Pradhan ◽  
Nintu Mandal
Keyword(s):  
Phosphate Rock ◽  
Rock Phosphate ◽  
Phosphorus Availability ◽  
Order Reaction ◽  
First Order Reaction ◽  
Alluvial Soils ◽  
Second Order Reaction ◽  
Maximum Correlation ◽  
First Order ◽  
Total P

The present study was undertaken to fractionate partially acidulated phosphate rock (PAPR) and evaluate its effect on Phosphorus availability in alluvial soils. For this purpose, low grade phosphate rock was collected from Udaipur, Rajasthan and acidulated at different degrees with sulphuric acid (H2SO4) (v/v)Results from an incubation study showed that the available fraction of P [Water soluble (WSP) and Citrate soluble (CSP)] increased with increasing degree of acidulation. The maximum WSP was obtained at 50% H2SO4 (52.30% of total P) and the maximum CSP was obtained at 80% H2SO4 (49.54% of total P). 50 % dissolution of rock phosphate was the best treatment and found to be at par with that of 60% and 80% but was significantly superior to rest of the treatments. The maximum WSP in the soil samples was obtained after acidulation with 50 %H2SO4 and the maximum Olsen’s P by the 14th day of incubation. An increasing trend was found at initial stages of incubation (7-14 days) with a notable decrease in the later stages. WSP demonstrated the maximum correlation at 40% dissolution(r = 96* for first order reaction, r =95* for second order reaction) while for Olsen’s P, the maximum correlation was found in initial rock phosphate sample (r =88* for first order reaction, r =94* for second order reaction). Kinetics analysis of the obtained rock phosphate demonstrated that the PARP has more influence on phosphorus release pattern as compared to the inorganic P (SSP).

scholarly journals Kinetic Studies for the Biosorption of Chromium Using Cherry Leaves (Muntingia calabura L.)

2014 ◽  
Vol 25 ◽  
pp. 6-11 ◽  
Author(s):  
R. Aathithya ◽  
J. Rajani Sowparnika ◽  
V. Balakrishnan
Keyword(s):  
Regression Coefficient ◽  
Kinetic Studies ◽  
Order Reaction ◽  
First Order Reaction ◽  
Standard Errors ◽  
Second Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Muntingia Calabura

Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.

scholarly journals Heptachlor degradation characteristics of a novel strain and its application

2018 ◽  
Vol 77 (8) ◽  
pp. 2113-2122
Author(s):  
Liping Qiu ◽  
Hu Wang ◽  
Xuntao Wang
Keyword(s):  
Gene Sequence ◽  
Degradation Products ◽  
Carbon Sources ◽  
Reaction Model ◽  
Order Reaction ◽  
Ribosomal Database Project ◽  
16S Rdna Gene ◽  
Practical Applications ◽  
First Order ◽  
Degrading Microorganism

Abstract With heptachlor as the sole carbon source, an effective heptachlor-degrading microorganism (named strain H) was isolated from the sludge of heptachlor-polluted sewage of a chemical plant, via enrichment, screening and purification. Strain H was identified as a facultative anaerobic Gram-negative bacterial strain belonging to genus Shigella based on the physiological-biochemical characteristics and the similarity analysis of its 16S rDNA gene sequence with the sequences logged in the Ribosomal Database Project and GenBank databases. When the optimal inoculation volume and the pH were 20% and 7.1–7.6, respectively, strain H was able to degrade heptachlor by more than 88.2% after130 h, with initial concentration of heptachlor being 300 μg/L at 30 ± 0.5 °C. It was also shown that strain H can grow on the degradation products of heptachlor such as 1-hydroxychlordene or heptachlor epoxide. Furthermore, additional carbon sources can accelerate the degradation rate of heptachlor because of co-metabolism. The degradation dynamics could be described by a first-order reaction model. A real-world field experiment demonstrated that strain H was effective in practical applications of heptachlor biodegradation in contaminated soil.

scholarly journals Determination of Chemical Stability of Two Oral Antidiabetics, Metformin and Repaglinide in the Solid State and Solutions Using LC-UV, LC-MS, and FT-IR Methods

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4430
Author(s):  
Anna Gumieniczek ◽  
Anna Berecka-Rycerz ◽  
Tomasz Mroczek ◽  
Krzysztof Wojtanowski
Keyword(s):  
High Temperature ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Magnesium Stearate ◽  
Oral Antidiabetics ◽  
First Order ◽  
First Order Kinetics ◽  
Ft Ir ◽  
The Stability

Firstly, metformin and repaglinide were degraded under high temperature/humidity, UV/VIS light, in different pH and oxidative conditions. Secondly, a new validated LC-UV method was examined, as to whether it validly determined these drugs in the presence of their degradation products and whether it is suitable for estimating degradation kinetics. Finally, the respective LC-MS method was used to identify the degradation products. In addition, using FT-IR method, the stability of metformin and repaglinide was scrutinized in the presence of polyvinylpyrrolidone (PVP), mannitol, magnesium stearate, and lactose. Significant degradation of metformin, following the first order kinetics, was observed in alkaline medium. In the case of repaglinide, the most significant and quickest degradation, following the first order kinetics, was observed in acidic and oxidative media (0.1 M HCl and 3% H2O2). Two new degradation products of metformin and nine new degradation products of repaglinide were detected and identified when the stressed samples were examined by our LC-MS method. What is more, the presence of PVP, mannitol, and magnesium stearate proved to affect the stability of metformin, while repaglinide stability was affected in the presence of PVP and magnesium stearate.

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